The present invention relates to the production of color or monochrome documents that contain graphic images and/or text.
There are now many types of businesses that would benefit from the capability of producing such documents but this capability is unavailable to smaller businesses because of cost. Currently available systems capable of producing such documents in short time frames presently cost several tens of thousands of dollars. Systems of this type are marketed under trade names such as Fiery(trademark), Splash(trademark) and Colorbus(trademark). These systems employ a computer, which may be of the PC type, a custom interface and a digital photocopier. Data needed for producing the document is stored on the computer""s hard drive and then read out to the photocopier.
The custom interface must have enough memory on it to store all of the data needed to print a full document page before it begins to output it to the photocopier. Consequently such an interface is expensive. The cost of such systems is further increased by their inability to use commercially available graphics, or image manipulation, programs, and the attendant need to create system-specific programs for performing desired image manipulations.
Even these expensive systems have been found to be relatively slow, due in substantial measure to inherent limits on the speed with which the data can be read from the hard drive.
It is a primary object of the present invention to provide a low cost capability of producing such documents.
Another object to the invention is to reduce the time needed to produce such documents.
A further object of the invention is to read into a computer data representing images present on printed documents.
The above and other objects are achieved, according to the present invention, by apparatus for printing a graphic image on a substrate, comprising: a computer containing at least one motherboard which carries a data bus and a random access memory, the computer being controlled by an operating system; means for storing image data in the random access memory; at least one card connected to the data bus and having a printing device interface and means for transferring stored image data from the random access memory to the interface; and a printing device connected to the interface for printing the graphic image on the substrate on the basis of stored image data transferred from the random access memory.
The printing device can be any device which will print a document in response to digital data. In the current state of the art, this encompasses printers which are constructed to be driven by a computer and digital photocopiers.
Objects according to the invention are further achieved by a method for printing a graphic image on a substrate, comprising: providing a computer containing at least one motherboard which carries a data bus and a random access memory, the computer being controlled by an operating system, at least one card connected to the data bus and having a printing device interface and means for transferring stored image data from the random access memory to the interface and a printing device connected to the interface; storing image data in the random access memory; transferring stored image data from the random access memory to the interface; and printing the graphic image on the substrate in the printing device on the basis of stored image data transferred from the random access memory.
Objects according to the invention are further achieved by the provision of a circuit card connectable in a card slot of a motherboard in a computer, the motherboard having a random access memory and a data bus connected to the memory, the circuit card comprising: a connector for connection to the data bus; an interface for connection to an external device; at least one circuit unit coupling the connector to the interface for effecting transfer of data between the random access memory and the external device; and a serial controller coupled between the circuit unit and the interface for transmitting a serial bit stream to the external device.
Apparatus according to the present invention can include any general purpose computer having a sufficiently large memory, in particular 128 MB or greater, any commercially available graphics software, such as Adobe Photoshop(copyright), a novel interface card, application-specific software and a connector for connecting the interface card to a printing device.
The software employed includes selected commercially available graphics software which will be used in its intended manner to perform all desired image manipulation, i.e., to prepare an image for hard copy reproduction in a printing device. The software, in addition to the commercially available graphics software, controls the card in a manner to control flow of image data from the computer RAM to the printing device. The RAM can store image data for one or more complete document pages and the rate of delivery of data from the computer RAM is limited essentially by the printing device capabilities.
In the following description, reference will be made to a digital photocopier, or copier for the sake of brevity, as one example of a printing device. It is to be understood, however, that the invention is applicable to other types of printing devices which print documents in response to digital signals.
The novel card, is preferably an interface card having a connector for connection, via a card slot on the computer motherboard, to a data bus, also on the computer motherboard. The card itself is relatively simple, and hence inexpensive. This card is characterized by the fact that it must have only a small amount of memory. Therefore, since the card is the only specialized hardware needed, an advantage of the invention is the low cost at which it can be implemented. In contrast, in prior art systems of the type mentioned at the outset, use is made of a card having a large memory sufficient to store all of the data needed to print a complete document. As a result, such a card is relatively expensive, and this adds significantly to the cost of the system.
According to one novel feature of the invention, the card carries a serial controller, or serial port, for example a UART, having serial control lines connected to the interface on the card. The interface, in turn, has serial control lines connectable to the digital photocopier or other external device. Because the serial controller is mounted directly on the card and is connected to control logic on the card, the serial controller can be directly controlled by programming written to implement procedures according to the invention. Therefore, the serial controller, or serial port, can be controlled precisely and directly even in a Windows(copyright) environment. A serial port connected to a computer in the conventional way would have to be controlled by the Windows(copyright) system, which does not allow a program to communicate directly with such a serial port.
The card employs a connector to enable it to be coupled to a bus on the computer motherboard. For example, state-of-the art computer motherboards are commonly provided with a PCI bus or an AGP bus, each which is used for transferring data at high rates.
The PCI bus is a special bus on new Intel compatible IBM PCs. The provision of a PCI bus is significant because it can transfer data at a rate of the order of 132 megabytes (MB) per second with a 33 MHz clock and this opens the possibility of providing an interface card which will be installed in a card slot on the computer motherboard to interface with the PCI bus, and which will be connected to the digital photocopier to provide a complete interface between the computer and the digital photocopier.
Alternatively, the motherboard may be provided with an AGP bus, in which case the card will have an AGP connector. The AGP bus is capable of transferring data at rates as high as 512 MB per second and AGP busses operating at higher rates are expected to be available. The AGP bus has the advantage that it is not multiplexed among several different sources and destinations and hence can transfer data at rates closer to its theoretical maximum. Thus, the AGP bus can enable printing and scanning to be performed at a higher rate than the PCI bus.
In addition, when the AGP bus is used, the result is that one interface is removed from the PCI bus, which allows data to be transferred at a higher rate from a hard drive to memory.
All of the memory for storing image data for printing a full document is in the computer, and more specifically the computer motherboard RAM that is tightly coupled to the computer CPU, and not on the separate card. Then when it is desired to output the image data to the photocopier, all of that image data already resides in memory. It doesn""t have to be transferred from one memory, or one memory region, to another, so that the time required to transfer that data is minimized.
The region of the memory which is to contain the image data may be designated a DMA (Direct Memory Access) buffer. The main program can transfer data directly from this memory region without requiring any preliminary transfer of data to another region of the memory.
Thus, a system according to the invention can be constructed from commercially available graphics software, a commercially available computer and a commercially available digital photocopier and only requires some specially prepared software and the novel interface card.